1. Field of the Invention
The present invention relates to a slide cover apparatus which is provided between a work station and a machining head unit with a tool spindle for preventing coolant, cutting chips or the like from invading into the zone for the machining head unit.
2. Discussion of the Related Art
In a known machining head unit of a machine tool or the like for effecting cutting operations on a workpiece, a spindle head with a tool spindle at its front end is provided to be movable toward and away from a work table. During machining operations, cutting chips, dust, coolant and so on scatter around the work table, which disadvantageously makes the working circumstance poor. Parts of the scattering cutting chips adhere to the spindle head, and this causes the machining unit to be liable to malfunction.
To overcome the aforementioned problems, an arrangement has been made wherein a partition wall or cover assembly having a tool-path hole through which the nose of a tool spindle of the head passes is provided between a work table and a machining head unit for preventing cutting chips from scattering thereby to adhere to the machining head unit. The partition wall assembly is practically used as of the type that a plurality of slide covers are telescopically extensible either in a vertical direction with the vertical movement of a tool spindle or in a horizontal direction with the horizontal movement of the tool spindle. However, the partition wall apparatus of the aforementioned type cannot be used for machine tools of the type wherein a tool spindle head is movable in three mutually perpendicular directions as is true with a machine tool such as, for example, machining center. Therefore, it is impossible to provide between the work table and the spindle head measures which can reliably prevent the scattering of cutting chips, coolant or the like.
Further, since the plural slide covers are moved with themselves being engaged with one another, there are required rails for supporting and guiding the slide covers and plural sub-covers engaged with a center cover for surrounding the same. All of these members have to be attached to a jig base. This not only makes the assembling work troublesome and time-consuming, but also makes the accessibility for machine inspection or repair difficult, because the members have to be removed and reassembled in a predetermined order.
Additionally, in the known cover apparatus, the slide covers are moved by the tool spindle which is inserted into the tool-path hole of the center cover, and nothing but the engagement of the tool spindle with the center cover is provided to synchronize movements of the spindle head and the slide covers. For this reason, once the tool spindle is taken out from the tool-path hole of the center cover for tool change purpose, the synchronization of the center cover and the tool spindle is lost, and difficulties would arise in subsequently inserting the tool spindle into the tool-path hole of the center cover. Furthermore, since the power to move the slide covers depends on the movement of the spindle head, excessive load acts upon the spindle head, thereby adversely affecting the machining accuracy of the workpiece.